1 files changed, 12 insertions, 29 deletions

diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index d31505b6f7a4..1a0d8c2a0354 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -43,6 +43,7 @@
 #include <linux/mutex.h>
 #include <linux/list.h>
 #include <linux/sysdev.h>
+#include <linux/gfp.h>
 
 #include <asm/page.h>
 #include <asm/pgalloc.h>
@@ -52,6 +53,8 @@
 
 #include <asm/xen/hypervisor.h>
 #include <asm/xen/hypercall.h>
+
+#include <xen/xen.h>
 #include <xen/interface/xen.h>
 #include <xen/interface/memory.h>
 #include <xen/xenbus.h>
@@ -66,8 +69,6 @@ struct balloon_stats {
         /* We aim for 'current allocation' == 'target allocation'. */
         unsigned long current_pages;
         unsigned long target_pages;
-        /* We may hit the hard limit in Xen. If we do then we remember it. */
-        unsigned long hard_limit;
         /*
          * Drivers may alter the memory reservation independently, but they
          * must inform the balloon driver so we avoid hitting the hard limit.
@@ -136,6 +137,8 @@ static void balloon_append(struct page *page)
                 list_add(&page->lru, &ballooned_pages);
                 balloon_stats.balloon_low++;
         }
+
+        totalram_pages--;
 }
 
 /* balloon_retrieve: rescue a page from the balloon, if it is not empty. */
@@ -156,6 +159,8 @@ static struct page *balloon_retrieve(void)
         else
                 balloon_stats.balloon_low--;
 
+        totalram_pages++;
+
         return page;
 }
 
@@ -181,7 +186,7 @@ static void balloon_alarm(unsigned long unused)
 
 static unsigned long current_target(void)
 {
-        unsigned long target = min(balloon_stats.target_pages, balloon_stats.hard_limit);
+        unsigned long target = balloon_stats.target_pages;
 
         target = min(target,
                      balloon_stats.current_pages +
@@ -217,23 +222,10 @@ static int increase_reservation(unsigned long nr_pages)
         set_xen_guest_handle(reservation.extent_start, frame_list);
         reservation.nr_extents = nr_pages;
         rc = HYPERVISOR_memory_op(XENMEM_populate_physmap, &reservation);
-        if (rc < nr_pages) {
-                if (rc > 0) {
-                        int ret;
-
-                        /* We hit the Xen hard limit: reprobe. */
-                        reservation.nr_extents = rc;
-                        ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
-                                                   &reservation);
-                        BUG_ON(ret != rc);
-                }
-                if (rc >= 0)
-                        balloon_stats.hard_limit = (balloon_stats.current_pages + rc -
-                                                    balloon_stats.driver_pages);
+        if (rc < 0)
                 goto out;
-        }
 
-        for (i = 0; i < nr_pages; i++) {
+        for (i = 0; i < rc; i++) {
                 page = balloon_retrieve();
                 BUG_ON(page == NULL);
 
@@ -259,13 +251,12 @@ static int increase_reservation(unsigned long nr_pages)
                 __free_page(page);
         }
 
-        balloon_stats.current_pages += nr_pages;
-        totalram_pages = balloon_stats.current_pages;
+        balloon_stats.current_pages += rc;
 
  out:
         spin_unlock_irqrestore(&balloon_lock, flags);
 
-        return 0;
+        return rc < 0 ? rc : rc != nr_pages;
 }
 
 static int decrease_reservation(unsigned long nr_pages)
@@ -323,7 +314,6 @@ static int decrease_reservation(unsigned long nr_pages)
         BUG_ON(ret != nr_pages);
 
         balloon_stats.current_pages -= nr_pages;
-        totalram_pages = balloon_stats.current_pages;
 
         spin_unlock_irqrestore(&balloon_lock, flags);
 
@@ -367,7 +357,6 @@ static void balloon_process(struct work_struct *work)
 static void balloon_set_new_target(unsigned long target)
 {
         /* No need for lock. Not read-modify-write updates. */
-        balloon_stats.hard_limit   = ~0UL;
         balloon_stats.target_pages = target;
         schedule_work(&balloon_worker);
 }
@@ -422,12 +411,10 @@ static int __init balloon_init(void)
         pr_info("xen_balloon: Initialising balloon driver.\n");
 
         balloon_stats.current_pages = min(xen_start_info->nr_pages, max_pfn);
-        totalram_pages   = balloon_stats.current_pages;
         balloon_stats.target_pages  = balloon_stats.current_pages;
         balloon_stats.balloon_low   = 0;
         balloon_stats.balloon_high  = 0;
         balloon_stats.driver_pages  = 0UL;
-        balloon_stats.hard_limit    = ~0UL;
 
         init_timer(&balloon_timer);
         balloon_timer.data = 0;
@@ -472,9 +459,6 @@ module_exit(balloon_exit);
 BALLOON_SHOW(current_kb, "%lu\n", PAGES2KB(balloon_stats.current_pages));
 BALLOON_SHOW(low_kb, "%lu\n", PAGES2KB(balloon_stats.balloon_low));
 BALLOON_SHOW(high_kb, "%lu\n", PAGES2KB(balloon_stats.balloon_high));
-BALLOON_SHOW(hard_limit_kb,
-             (balloon_stats.hard_limit!=~0UL) ? "%lu\n" : "???\n",
-             (balloon_stats.hard_limit!=~0UL) ? PAGES2KB(balloon_stats.hard_limit) : 0);
 BALLOON_SHOW(driver_kb, "%lu\n", PAGES2KB(balloon_stats.driver_pages));
 
 static ssize_t show_target_kb(struct sys_device *dev, struct sysdev_attribute *attr,
@@ -544,7 +528,6 @@ static struct attribute *balloon_info_attrs[] = {
         &attr_current_kb.attr,
         &attr_low_kb.attr,
         &attr_high_kb.attr,
-        &attr_hard_limit_kb.attr,
         &attr_driver_kb.attr,
         NULL
 };